Evaluate $i^6+i^{16}+i^{-26}$.
Answer: We have $i^6 = i^4\cdot i^2 = 1\cdot (-1) = -1$.  We also have $i^{16} = (i^4)^4 = 1^4 =1$, and $i^{-26} = 1/i^{26} = 1/(i^{24}\cdot i^2) = 1/[1\cdot (-1)] = -1$. So, adding these three results gives $i^6 + i^{16} + i^{-26} = -1+1-1 = \boxed{-1}$.